Retaining walls to prevent earth embankments from sliding and slumping are well known. Conventional walls are constructed from materials such as wood ties or blocks of stone or concrete. The rows of a wall are often offset with respect to one another to form a wall face that is inclined with respect to the vertical.
Retaining walls formed from interconnectable blocks are particularly popular as they are sturdy and relatively easy to construct. Many block designs and wall configurations have been developed. Examples of such designs are shown in the following patents:
U.S. Pat. 2,892,340 to Fort PA1 U.S. Pat. 4,671,706 to Giardini PA1 U.S. Pat. 4,825,619 to Forsberg PA1 U.S. Pat. 4,860,505 to Bender PA1 U.S. Pat. 4,920,712 to Dean, Jr. PA1 U.S. Pat. 4,964,761 to Rossi PA1 U.S. Pat. 4,965,979 to Larrivee et al. PA1 U.S. Pat. 5,017,049 to Sievert PA1 U.S. Pat. 5,044,834 to Janopaul, Jr. PA1 U.S. Pat. 5,161,918 to Hodel
The wall blocks and wall constructions disclosed in the foregoing patents generally relate to blocks that use a system of drilled holes and aligning pegs or a tongue and groove arrangement to position and interlock together the individual blocks of the retaining wall.
Tongue and groove interlocking blocks suffer from the disadvantage that they are difficult if not impossible to form into a curved configuration without using specially shaped blocks. It is often necessary to have a curve in a retaining wall to accommodate curves in the terrain.
Blocks that use drilled holes and aligning pegs tend to be time consuming to interfit together. The additional cost of the aligning pegs and specially drilled holes in blocks makes the blocks more expensive to manufacture. The result is a retaining wall that is costlier to construct in terms of both time and materials.